Nuclear magnetic resonance hydride complexes

Solid-state nuclear magnetic resonance (NMR) has been extensively used to assess structural properties, electronic parameters and diffusion behavior of the hydride phases of numerous metals and alloys using mostly transient NMR techniques or low-resolution spectroscopy [3]. The NMR relaxation times are extremely useful to assess various diffusion processes over very wide ranges of hydrogen mobility in crystalline and amorphous phases [3]. In addition, several borohydrides [4-6] and alanates [7-11] have also been characterized by these conventional solid-state NMR methods over the years where most attention was on rotation dynamics of the BHT, A1H4, and AlHe anions detection of order-disorder phase transitions or thermal decomposition. There has been little indication of fast long-range diffusion behavior in any complex hydride studied by NMR to date [4-11]. 

Tetrakis(organophosphorus)metal hydrides (containing one, two, three, or four hydride nuclei) have recently attracted considerable attention in connection with their stereochemical behavior1 and reaction chemistry.2 Detailed nuclear magnetic resonance studies and line-shape analyses have substantiated stereochemical nonrigidity in many of these complexes in solution and have yielded mechanistic information about the intramolecular-exchange processes.3... 

Characterize the material properties of each new generation of complex hydrides to aid in further improvements. Compare different material responses using kinetics experiments coupled with analytic techniques such as X-ray, electron spin resonance (ESR), nuclear magnetic resonance (NMR), Auger spectroscopy, etc. 

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